Begin by mixing together flour, sugar, baking powder, and salt in a large bowl. Cut in the shortening until the mixture resembles coarse crumbs.

Gradually add cold water and mix until a dough forms. Roll out the dough on a floured surface, then fit it snugly into a 9-inch pie plate.

While preparing the filling, preheat your oven to 325°F (163°C).

In a microwave-safe bowl, melt the butter covered with a paper towel for about 1 minute and ensure it’s slightly cool.

In a large mixing bowl, beat the eggs until fluffy, then add vanilla, flour, and both sugars, thoroughly combining the ingredients.

Gradually incorporate the cooled melted butter, mixing until achieving a glossy filling. Gently fold in chocolate chips and walnuts.

Carefully pour the filling into the prepared pie shell and smooth the top.

Place a rimmed baking sheet on a lower rack in the oven to catch any possible drippings.

Bake the pie for approximately 1 hour, until the edges are set and the center is slightly jiggly.

Once baked, allow it to cool at room temperature for 30-60 minutes before slicing.